Mechanically cleanable filter



March 29, 1949. A. J. EDUARDS 2,465,579

MECHANICALLY GLEANABLE FILTER Filed NOV. 27, 1944 lugs Patented Mar. 29, 1949 UNITED "STATES PATENT OFFICE Application November 27, 1944, Serial'No. 565,320 In Sweden May '27, 1940 6 Claims. .1

The present invention relates to a filter for liquids, which is cleanable while in use. It is of great importance, especially in the case of filters for fuel for internal combustion .motors that the filter can be quickly and efficiently cleaned without disturbing the running of the machine. The invention relates .more specifically to that type of cleanable filter, which comprises a number of relatively movable members. Hitherto known filters of this typehave comprised. metal discs, or rings of wire superimposed one upon the other and which have been provided with notches or have been roughened on theiradjacent surfaces,

so that fine channels .are formed between the discs or rings through which the liquid must pass and where solidparticles in the liquid which cannot pass through the channels are caught. In

some cases the desired roughness has been obtained by spirally twisting the wires. Channels formed in this way sufier however from the disadvantage that their cross-sectional area remains unchanged even when the discs for rings are turned relative each other becausethe material is so rigid that the projections on one member cannot enter the depressions in the other, but only slide across the projections on the latter. Impurities, which have been caughtin the channels will therefore only be moved peripherally when the members are turned and will not be forced out of the channels to any great extent,

but remain instead more or less compressed between the projections. The cleaning of the filter during running will therefore be very unsatisfactory, when it is considered howimportant it is, especially in the case of moderniDiesel engines to remove carefully even the smallest solid particles so that they do not obstruct the very fine channels of the fuel nozzles.

These disadvantages are eliminated in the filter,

according to presentinvention, which is characno terized mainly therein, that the filterrings consist of intertwined wires or the like. This embodiment of the filterrings entails considerable advantages since when the filter begins to function poorly during use due to cloggingand therings areturned relatively to each other, the irregularities in the contacting surfaces, which have been formed by the intertwining of the wires will be subjected to continuous alterations in form because of the yielding movement of the intertwined members when the projections on one member pass over those of the other. The crosssectional area of the channels in the filter will be in this manner alternately be increased and decreased resulting in a grinding (crushing) or 2 vibrating movement. This together with the irregularities in'the radial direction ofthe rings due to the spiral form caused by the twisting of the Wires causes a movement of the solid particles trapped in the channels. This movement takes place outwardly due to the influence of .the centrifugal force, in other words in a direction away from the purified liquid, which has already passed through thelfilter.

The'accompanying drawing shows an embodiment of the invention specially suitable as a filter in the fuel duct of an automobile motor.

In the drawing:

Fig.1 is a vertical section through the complete filter in working condition.

vFig. 2 is a cross section along the line 11-11 in Fig. 1.

Fig. S is vertical section through the filter propenand Figs. 4 and 5 show two different filterrings.

In the drawing the numeral I designates the filtercasing and 2 the hell with which filters are usually provided and which is fixed to the casing l in any suitable manner, for instance by means .of a disc 4 having perforations 3 which is detachably disposed in the casing l and to which is fixed an internally threaded sleeve 5, there being a screw 6 engaging the sleeve 5 which presses the bell against the lower end of the easing. In the'casing l is a filter body comprisinga number of :rods Lattached to a disc 8 and a circular series of rings 9 of wire, which are arranged in close contact with each other and surround the rods I as shown in Figs. 1 and 3. ,The rings 9 are disposed between two discs in and II, which are slidable on the rods 1 and which,

with the aid of springs l2 disposed between the discs 8 and II, maintain the rings 9 pressed against each other. Each of therings 9 is formed ..of two or more fine wires intertwined or twisted together and shaped, as by being curved about a cylindrical .form, to .provide an open ring of a diameter suitable :to"fit over the circular series of rods 1. vAs a result of this twisting or inter- ;twining the adjacent surfaces of the rings 9 will have a great number of projections, which when two rings are in close contact with each other form fine channels for the passage of the liquid to be filtered.

From Figs. 4 and 5 it will be seen that some of the rings 9 are provided with an inwardly directed arm l3 (Fig. 4) and others with an outwardly directed arm M (Fig. 5). The rings 9 are suitably arranged in the filter body so that every other ring has an inwardly directed arm 13 and turning motion will be imparted to those of the rings 9 having inwardly directed arms l3, while those of the rings having outwardly directedarms 1;

I4 will be prevented from taking part in the motion. The result will be that there will be arelative movement between the. contacting surfacesof the rings and in the example shown this movement will be pheripherally directed.

The axle i6 is turned by the aid of a handle I1 so positioned that it is accessible when the filter is in use.

The casing I is pierced'at its top by two-pipes, of which pipe I8 is for connection to the inlet pipe for unfiltered liquid and the pipe I9 is for connection to the outlet for filtered liquid. In the example shown the disc I0 is pierced by a hole 20 towhich is connected a pipe 2| located within the casing and connectedto pipe I9 whereby the inside of the filter is connected to the outlet.

-The filter functions in thefollowing manner. The unfiltered liquid entersthe casing I through the pipe l8 and fills the casing to such a level that the liquid covers the whole or the greater part of the filter formed by the rings 9. Due to the difference in pressure existing between the inlet l8 and the outlet l9'the liquid forces its way through the previously mentioned fine channels, formed by the irregularities in the connecting surfaces, to the inside of the filter from where it continues through the hole in the disc II] to the pipe 2i and passes out through the pipe I9.

Impurities in the liquid are caught in the channels between the rings 9, so that only pure liquid enters the cavity of the filter.

When the filter has become clogged byimpurities the axle I6 is turned with the aid of the handle l1, either continuously in a single direction, or with an oscillating movement so that ad- I jacent rings 9 perform a relative movement, whereby the impurities are loosened from the rings. It is easily seen that this turning movement can be carried out without diificulty at any time independently of the flow of liquid through the filter, and that consequently it is not necessary to interrupt the filtering operation to clean the filter. It has been found that this method of cleaning the filter is very effective, so that even badly clogged filters are completely cleaned after only a few turns of the handle.

Other embodiments than that shown and described can be used, for instance such embodiments in which the rings are shaken or vibrated while being turned to loosen the solidparticlesfrom the rings. The spiral form of the channels due to the intertwining of the wires has been:

4 found to specially facilitate the removal of impurities.

What I claim is:

1. A filter for liquids comprising a plurality of rings arranged in close contact and means for causing relative movement between adjacent rings, the said rings being formed of intertwined wires presenting irregular contacting surfaces between the adjacent rings. v v

' 2. A filter for liquids comprising a plurality of rings superimposed one upon the other in close contact and means for imparting a relative movement between adjacent rings, the said rings being formed of intertwined wires presenting irregular contacting surfaces between the adjacent rings.

3. A filter for. liquids comprising a plurality of rings arranged in close contact, each of said rings being formed of a plurality of intertwined wires presenting irregular contacting surfaces between UNITED STATES PATENTS Number Name Date 404,911 Hyatt June 11, 1889v 559,440 Conrader i May 5, 1896 1,150,910 Warmington Aug. 24, 1915 1,581,998 I Fulcher Apr. 20, 1926 1,926,557 Perkins Sept. 12, 1933 2,035,758 Pierce Mar. 31, 1936 2,197,971 Elze et al Apr. 23, -1940 2,308,865 Davis Jan. 19, .1943 1 2,365,525 Cox Dec. 19, 1944 FOREIGN PATENTS Number Country I Date 828,262 France Feb. 7, 1938 T the rings relative to its the adjacent rings, projections attached to some of the rings'and means engaging the said projections for imparting a movement to the rings.

- 4. A filter for liquids comprising a plurality of rings arranged in close contact, each of said rings being formed of a plurality of intertwined wires presenting irregular contacting surfaces between",

the adjacent rings, projections attached to some of the rings and extendingin a direction opposite to the flow of liquid and means engaging the said projections for restraining the said rings against movement.

5. A filter for liquids comprising a plurality of 7 rings arranged 'in-closecontact, each of the said I rings being formed of a plurality'of intertwined wires presenting irregular contacting surfaces between the adjacent rings, means for moving every other ring-in a peripheraldirection, and means for restraining the other rings from movement. Q 6. A filter for liquids comprising a number of rings arranged in close contact, each of said rings being'formed of a plurality of intertwined wires presenting irregular contacting'surfaces between the adjacent rings, means for oscillating some of adjacent rings.

ALBERT J. EDUARDS.

I REFERENCES CITED 

